Illegal copying and distribution of multimedia digital content (audio and video) is prevalent in recent years, especially using the Internet. This illegal copying and distribution is an infringement of copyright protection laws and cause financial damages to the rightful owners of the digital content. It is therefore of great interest to find methods that would mitigate illegal copying and/or distribution of multimedia files without offending rightful usage.
Methods for usage rights enforcement of digital media are known. Some methods are desired to monitor digital copying of the digital content. For example, the system described in U.S. Pat. No. 6,115,533 authenticates an information signal prior to mass duplication of the signal by analyzing the signal to detect the presence or absence of a security signal therein, inserting a security signal into the information signal, and recording the modified signal only if no security signal was detected. U.S. Pat. No. 6,167,136 describes a method for securely storing analog or digital data on a data storage medium: an analog information signal is combined with a noise signal. The composite noise and information signal is encrypted with a key, which is derived from the noise signal. The encrypted composite signal is compressed and then recorded on the data storage medium along with an encrypted value of the key. The storage medium data is read, decompressed, and decrypted using a decryption key derived from the stored encrypted key. The data is then converted to an analog signal and combined with a noise correction signal derived from said key to eliminate the noise signal added to the analog information signal before storing the signal on the data storage medium.
Systems that run the MS-Windows™ operating system (OS) are equipped with the OS's Digital Rights Management (DRM) that supplies standard protection to digital content. The DRM consist of a set of filters, such as decryption, decoding and others that manipulate and channel the digital content to the screen card and/or sound card. Each filter exposes a set of virtual pins to connect to filters preceding and succeeding it. Each filter receives the digital content from its predecessor, manipulates it and transfers it to the next filter on the graph. While this traditional component may be viable solution for some digital content, it provides insufficient security to protect premium digital content. Since it's a layered component, at each layer a hacker can insert infringing software that connects between two filters (by the virtual pins) and redirect the digital content to the disk. A hacker may also substitute one of the OS supplied filters with his/hers own, hence hacking into the video path and again, redirect the digital content to the disk.
Other solutions wrap the digital content within encryption and business rules envelope, The rules are stored in a local database protected by encryption. This solution supplies better digital content management capabilities but lacks on the security side. If the local database is breached, the hacker can change the policy of the digital content. Furthermore the digital content encryption is easier to be breached in these types of solutions since it's not an integral part of the digital content player.
While these methods make illegal copying difficult, it is commonly believed that none of the existing methods provides sufficient security determined and competent opponents. Furthermore, once a certain protection method is cracked, the cracking tools and methods may become available to a large community via the Internet, thereby render the digital content effectively unprotected, and therefore an updateable solution is highly desireable.
It is foreseeable that as the availability of disc space and bandwidth for data communication will increase, illegal distribution of video and audio digital content will become prevalent unless effective counter-measures will be taken.